An important function of any printing or imaging system is accurately placing an image in a desired location on the final receiving medium. Many printers and imaging systems utilize mechanical media measurement and/or media position location systems to effect image placement. These systems will typically calculate the width and length of the media, as well as the position of the media relative to the image-generating components of the printer or imaging system.
Many prior art printers are limited to handling two sizes of media, such as A and A4 size media. These printers often incorporate fixed-position media width sensors to detect the size of the media, with one sensor being provided for each size. A common sensor that is utilized is a photo-reflective sensor that detects the presence or absence of a sheet of media at a particular location.
As the number of different sizes of media to be printed increases, the use of a separate fixed-position sensor for each media size becomes less desirable. Additionally, the accuracy of the mechanical subsystems used to determine the media width and media position is subject to fluctuation due to component variations and assembly tolerances in the subsystems. In printers utilizing photo-reflective sensors to detect the edges of a sheet of media, the exact point of detection of the media will vary depending upon the reflectivity of different media types, as well as manufacturing variations from one sensor to another.
The present invention is directed to a method for calibrating a printer to align an image on a final receiving substrate. A test image is printed and the margins between the image and the edges of the media are measured. These measured margin values are then utilized to adjust calibration factors that calibrate the printer to accurately place the image on the final receiving substrate.